6,629 research outputs found
Modeling Routing Overhead Generated by Wireless Proactive Routing Protocols
In this paper, we present a detailed framework consisting of modeling of
routing overhead generated by three widely used proactive routing protocols;
Destination-Sequenced Distance Vector (DSDV), Fish-eye State Routing (FSR) and
Optimized Link State Routing (OLSR). The questions like, how these protocols
differ from each other on the basis of implementing different routing
strategies, how neighbor estimation errors affect broadcast of route requests,
how reduction of broadcast overhead achieves bandwidth, how to cope with the
problem of mobility and density, etc, are attempted to respond. In all of the
above mentioned situations, routing overhead and delay generated by the chosen
protocols can exactly be calculated from our modeled equations. Finally, we
analyze the performance of selected routing protocols using our proposed
framework in NS-2 by considering different performance parameters; Route
REQuest (RREQ) packet generation, End-to-End Delay (E2ED) and Normalized
Routing Load (NRL) with respect to varying rates of mobility and density of
nodes in the underlying wireless network
SPIDER: Fault Resilient SDN Pipeline with Recovery Delay Guarantees
When dealing with node or link failures in Software Defined Networking (SDN),
the network capability to establish an alternative path depends on controller
reachability and on the round trip times (RTTs) between controller and involved
switches. Moreover, current SDN data plane abstractions for failure detection
(e.g. OpenFlow "Fast-failover") do not allow programmers to tweak switches'
detection mechanism, thus leaving SDN operators still relying on proprietary
management interfaces (when available) to achieve guaranteed detection and
recovery delays. We propose SPIDER, an OpenFlow-like pipeline design that
provides i) a detection mechanism based on switches' periodic link probing and
ii) fast reroute of traffic flows even in case of distant failures, regardless
of controller availability. SPIDER can be implemented using stateful data plane
abstractions such as OpenState or Open vSwitch, and it offers guaranteed short
(i.e. ms) failure detection and recovery delays, with a configurable trade off
between overhead and failover responsiveness. We present here the SPIDER
pipeline design, behavioral model, and analysis on flow tables' memory impact.
We also implemented and experimentally validated SPIDER using OpenState (an
OpenFlow 1.3 extension for stateful packet processing), showing numerical
results on its performance in terms of recovery latency and packet losses.Comment: 8 page
Energy management in communication networks: a journey through modelling and optimization glasses
The widespread proliferation of Internet and wireless applications has
produced a significant increase of ICT energy footprint. As a response, in the
last five years, significant efforts have been undertaken to include
energy-awareness into network management. Several green networking frameworks
have been proposed by carefully managing the network routing and the power
state of network devices.
Even though approaches proposed differ based on network technologies and
sleep modes of nodes and interfaces, they all aim at tailoring the active
network resources to the varying traffic needs in order to minimize energy
consumption. From a modeling point of view, this has several commonalities with
classical network design and routing problems, even if with different
objectives and in a dynamic context.
With most researchers focused on addressing the complex and crucial
technological aspects of green networking schemes, there has been so far little
attention on understanding the modeling similarities and differences of
proposed solutions. This paper fills the gap surveying the literature with
optimization modeling glasses, following a tutorial approach that guides
through the different components of the models with a unified symbolism. A
detailed classification of the previous work based on the modeling issues
included is also proposed
A Case for Time Slotted Channel Hopping for ICN in the IoT
Recent proposals to simplify the operation of the IoT include the use of
Information Centric Networking (ICN) paradigms. While this is promising,
several challenges remain. In this paper, our core contributions (a) leverage
ICN communication patterns to dynamically optimize the use of TSCH (Time
Slotted Channel Hopping), a wireless link layer technology increasingly popular
in the IoT, and (b) make IoT-style routing adaptive to names, resources, and
traffic patterns throughout the network--both without cross-layering. Through a
series of experiments on the FIT IoT-LAB interconnecting typical IoT hardware,
we find that our approach is fully robust against wireless interference, and
almost halves the energy consumed for transmission when compared to CSMA. Most
importantly, our adaptive scheduling prevents the time-slotted MAC layer from
sacrificing throughput and delay
IPv6 Network Mobility
Network Authentication, Authorization, and Accounting has
been used since before the days of the Internet as we know it
today. Authentication asks the question, “Who or what are
you?” Authorization asks, “What are you allowed to do?” And fi nally,
accounting wants to know, “What did you do?” These fundamental
security building blocks are being used in expanded ways today. The
fi rst part of this two-part series focused on the overall concepts of
AAA, the elements involved in AAA communications, and highlevel
approaches to achieving specifi c AAA goals. It was published in
IPJ Volume 10, No. 1[0]. This second part of the series discusses the
protocols involved, specifi c applications of AAA, and considerations
for the future of AAA
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